Within the Standard Model, a review of the current determination of the sides and angles of the CKM unitarity triangle is presented, using experimental constraints from the measurements of K , V u b /V c b , Δm d and from the limit on Δm s , available by summer 2000. Peculiar attention has been devoted to the determination of theoretical uncertainties. Results from the experimental search on B 0 s - B 0 s oscillations are introduced in the present analysis using the likelihood ratio approach.Different fitting techniques have been compared.